Intrauterine synechiae or adhesions, also known, in the most severe cases, as Asherman's syndrome, consist of partial or total adhesion of the cervical and/or uterine body walls. They are often accompanied by chronic abdominal pain and dysmenorrhea, and may lead to mechanical infertility due to implantation failure. It is acknowledged today that intrauterine synechiae are most often due to a surgical procedure performed in the uterine cavity, such as Cesarean section, endometrial resection, curettage subsequent to childbirth or miscarriage, etc.
Once diagnosed, intrauterine synechiae are generally treated by operative hysteroscopy, using micro scissors introduced into the uterine cavity to section the fibrous synechia bridges. The synechia reformation rate remains, however, relatively high, and may even reach more than 40% in cases of severe synechiae.
Currently, there is little or no progress in preventing synechiae. A solution may consist in placing a physical barrier in the uterine cavity of patients at risk, in order to prevent tissue adhesion. However, the products developed to date are unsatisfactory.
Thus, gels based on hyaluronic acid and/or polyethylene glycol have been developed (Hyalobarrier® from Nordic Pharma, SprayShield® from Covidien), to be deposited on the uterine wall after a surgical procedure. However, particularly due to their galenic gel form, these products are eliminated very rapidly, and have a residence time in the uterus lower on average than 24 hours. However, it is known that synechiae develop within 1 to 8 days after the occurrence of uterine trauma. The too-rapid elimination of these gels thus prevents them from acting satisfactorily to prevent the formation of fibrous synechia bridges.
A film composed of synthetic hyaluronic acid, associated with a carboxymethyl cellulose/glycerol substrate, has also been developed (Seprafilm® from Genzyme). If this type of film is commonly used to prevent postoperative adhesions in abdominal surgery, it is not satisfactory for intrauterine synechiae. Indeed, the morphology and the mechanical properties of the film make it difficult or impossible to introduce it into the uterine cavity via the cervix.
Also known from the document U.S. Pat. No. 7,202,281 is a composition comprising copolymers based on poly-lactic acid (PLA) and polyethylene glycol (PEG) having a molecular weight of 6,000, used to form an anti-adhesion film for preventing synechiae particularly in the abdominal region. Such a film is however not satisfactory in the context of preventing intrauterine synechiae.
There is thus a genuine need for a product that can be easily positioned in the uterine cavity and whose physical and chemical properties make it possible to prevent the formation of synechiae, particularly in patients having undergone a surgical procedure in the uterine cavity.